Sealing means for valve spindle

ABSTRACT

A large manually operated leak-proof corrosion-proof low-cost shut-off or stop valve for handling high pressure refrigerant liquids and/or gases comprises a valve body formed of two sheet metal hemispheres welded to the periphery of a circular metal valve plate having a fluid passage therethrough and hollow cylindrical metal tubes welded to the hemispheres along the edges of circular holes cut in the hemispheres. One tube on each hemisphere serves for fluid flow. Another internally and externally threaded tube on one hemisphere serves as a valve sleeve through which a rotatable and axially shiftable externally threaded valve spindle extends. The inner end of the valve spindle is secured to a valve disc which releasably engages a valve seat around the fluid flow passage in the valve plate. The outer end of the valve spindle is secured to the hub of a hand-wheel which is rotatable to open and close the valve. A hollow internally threaded bonnet is screwed on to the externally threaded outer end of the valve sleeve and entraps sealing materials so as to form a seal between the valve spindle and the valve sleeve and also entraps O-rings between the valve spindle and the bonnet. Unscrewing of the bonnet affords access to the sealing materials and O-ring and, as the bonnet moves axially, it also axially shifts the hand-wheel off of the outer end of the valve spindle.

BACKGROUND OF THE INVENTION

1. Field of Use

This invention relates generally to relatively large manually operatedleak-proof and corrosion-proof shut-off or stop valves for handling highpressure liquids and/or gases such as are used in refrigeration systemsor the like.

In particular, the invention relates to sealing means for a valvespindle which extends through a sleeve into the valve body.

2. Description of the Prior Art

Large industrial and commercial refrigeration systems employrefrigerants, such as ammonia, freon and the like, which are circulatedthrough the system at high pressure in gaseous and liquid form. Theserefrigerants are costly (presently as much as $12.00 per pound) and anyleakage in a large system not only reduces system efficiency but adds tocost of operation. Such systems require relatively large manuallyoperable shut-off or stop valves to control fluid flow. Heretofore, suchvalves typically comprised a onepiece cast iron valve body withintegrally formed threaded inlet and outlet flow tubes to which threadedpipe ends were connected. A rotatable valve spindle with a handle wheelon its outer end and a valve disc on its inner end extended from thevalve body. Various types of valve spindle stuffing box arrangementswere employed to seal against leakage of high pressure past the valvespindle. Also, various valve seating arrangements were employed toensure proper valve closure. Threaded connections on the valve body veryoften proved to be prone to fluid loss. Furthermore, valve seat andvalve disc designs and valve spindle stuffing box designs--oftendictated by the configuration of a cast iron valve body--weresusceptible to wear requiring servicing and replacement. Again, priorart valve designs often required substantial disassembly of the valve toenable servicing and part-replacement. Typically, disassembly of thestuffing box for the valve spindle first required removal of thehand-wheel from the valve spindle. Not uncommonly, the hand-wheel wasforce-fitted in place and its removal required use of a wheel or bearingpuller. The following U.S. Patents illustrate the state of the art andshow various attempts to avoid the use of threaded cast-iron valvehousings to provide improved valve structures, to improve valve seals,to facilitate repairs and to employ technology aimed at cost reduction.U.S. Pat. Nos. 3,743,246 and 4,265,427 show gate valve bodies usinggeometrically shaped welded sections; U.S. Pat. Nos. 3,580,268,3,678,556 and 3,518,742 are of a similar thrust; U.S. Pat. Nos.3,523,551, 3,275,290, 4,322,058 and 3,337,183 concern stuffing boxarrangements for valve stems.

SUMMARY OF THE INVENTION

A large manually operated leak-proof corrosion-proof low-cost shut-offor stop valve for handling high pressure refrigerant liquids and/orgases comprises a valve body formed of two sheet metal hemisphereswelded to the periphery of a circular metal valve plate having a fluidpassage therethrough and hollow cylindrical metal tubes welded to thehemispheres along the edges of circular holes cut in the hemispheres.One tube on each hemisphere serves for fluid flow. Another internallyand externally threaded tube on one hemisphere serves as a valve sleevethrough which a rotatable and axially shiftable externally threadedvalve spindle extends. The inner end of the valve spindle is secured toa valve disc which releasably engages a valve seat around the fluid flowpassage in the valve plate. The outer end of the valve spindle issecured to the hub of a hand-wheel which is rotatable to open and closethe valve. A hollow internally threaded bonnet is screwed on to theexternally threaded outer end of the valve sleeve and entraps sealingmaterials so as to form a seal between the valve spindle and the valvesleeve and also entraps O-rings between the valve spindle and thebonnet. Unscrewing of the bonnet affords access to the sealing materialsand O-ring and, as the bonnet moves axially, it also axially shifts thehand-wheel off of the outer end of the valve spindle.

A valve in accordance with the invention offers several advantages overthe prior art. For example, redundance of sealing means ensures a betterseal. Seal replacement is possible merely by removing the bonnet and thehand-wheel and there is no need to remove the valve spindle or disturbinternal components to gain access to the sealing means. Removal of thehand-wheel from the valve spindle is easy to accomplish and is aided bythe unscrewing action of the bonnet, whereas prior art hand-wheelattachment arrangements involving force-fits often required bearingpullers for disassembly. Use of washers and O-rings as part of thesealing means is economical and enables easy assembly and replacement ofsuch parts, although the use of stacked stuffing or packing rings iseasily provided for, if need be. Various types and shapes of bonnetdesigns are easily provided for even though the same valve sleeve isemployed. Or, various types and shapes of sleeve designs (whetherone-piece or two-piece) are easily provided for. Other objects andadvantages of the invention will hereinafter appear.

DRAWINGS

FIG. 1 is a perspective view of a valve in accordance with theinvention;

FIG. 2 is an enlarged cross-section view of the valve taken on line 2--2of FIG. 1;

FIG. 3 is a schematic diagram showing the planar and linearrelationships of the holes formed in the spherical valve body shown inFIG. 2;

FIG. 4 is an enlarged top plan view of a portion of the hand-wheel andits associated spindle and roll pin taken on line 4--4 of FIG. 3;

FIG. 5 is an isometric exploded view of the components shown in FIG. 2;

FIG. 6 is an isometric exploded view of a valve plate, the inner orlower end of the valve spindle, a valve disc and C-ring shown in FIG. 2;

FIG. 7 is a cross-section view showing an embodiment of a valve seat anda valve disc which differs from that shown in FIGS. 2 and 6;

FIG. 8 is a view similar to FIG. 7 but showing still another embodiment;

FIG. 9 is a cross-section view showing an embodiment of a valve sleeveand sleeve bonnet which differs from that shown in FIG. 2;

FIG. 10 is an end view of the bonnet shown in FIG. 9;

FIG. 11 is a view similar to FIG. 9 but showing still anotherembodiment;

FIG. 12 is an end view of the bonnet shown in FIG. 11;

FIG. 13 is a view similar to FIGS. 9 and 11 of yet another embodiment;and

FIG. 14 is a view similar to FIGS. 9, 11 and 13 but showing anothermeans for securing a valve sleeve to the valve body.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIGS. 1 and 2, there is shown a valve 10 in accordance withthe invention. Valve 10 preferably takes the form of a large manuallyoperated leak-proof corrosion-proof low-cost shut-off or stop valve forhandling high pressure refrigerant liquids and/or gases such as are usedin refrigeration systems. Valve 10 comprises a spherical valve body 12formed of two sheet metal hemispherical sections 14 and 16 welded to theperiphery of a circular metal valve plate 18 which has a circular flowaperture or fluid passage 20 therethrough. Two hollow cylindrical metalfluid flow tubes 22 and 24 are welded to the hemispherical sections 14and 16, respectively, along the edges of circular holes 26 and 28,respectively, which are cut in the sections.

A hollow cylindrical metal valve spindle sleeve 30, internally andexternally threaded as at 32 and 34, respectively, is welded tohemispherical section 16 and communicates with a circular hole 35 formedin the section. A rotatable and axially shiftable valve spindle 36extends through sleeve 30 and is externally threaded as at 38 to engagethe threads 32.

The cylindrical inner end 40 of the valve spindle 36 extends into acylindrical recess 42 in a metal valve disc 44 which releasably engagesa valve seat 46 formed around fluid flow passage 20 in valve plate 18.The valve disc 44 is secured to the valve spindle 36 by a metal C-ring48 of circular cross-section which engages an annular groove 50 formedin the periphery of the cylindrical inner end 40 of the valve spindle 36and a registering annular groove 52 formed in the peripheral wall 54 ofthe cylindrical recess 42 in the valve disc 44, as FIGS. 2 and 6 show.Recess 42 is chamfered as at 41 to facilitate ring insertion.

The cylindrical outer end 56 of the valve spindle 36 extends into acylindrical bore 58 in the hub 60 of a hand-wheel 62 which is rotatableto open and close the valve. The hand-wheel 62 is secured to spindle 36by a removable roll pin 64, having a flange 65, which pin fits into apin hole 66 formed by mating or registering recesses 68 and 70 formed inthe periphery of the outer end 56 of the valve spindle 36 and in theperipheral wall 72 of the bore 58 in the hub 60 of the hand-wheel 62,respectively, as FIGS. 2, 4 and 5 show.

A hollow bonnet 74 internally threaded as at 76 is screwed on to theexternal threads 34 on the outer end of the valve spindle sleeve 30 andentraps sealing materials 78 so as to form a seal between the valvespindle 36 and the valve spindle sleeve 30 and also entraps a pluralityof O-rings 80 between the valve spindle 36 and the bonnet 74. Unscrewingof the bonnet 74 affords access to the sealing materials 78 and O-rings80 and, as the bonnet moves axially, it also axially shifts thehand-wheel 62 off of the outer end 56 of the valve spindle 36. As thisoccurs, the wheel hub 60 engages the roll pin flange 65 to force theroll pin 64 out of the pin hole 66.

The metal components thus far described could be formed of any suitablemetal. But, a valve 10 designed for use with fluids tending to causerust, corrosion or oxidation is preferably fabricated of stainlesssteel. Furthermore, the hemispherical sections 14 and 16, the valveplate 18, the tubes 22 and 24 and the sleeve 30 are preferably formed ofseamless materials to enhance their strength in a high pressure system.The holes 26, 28 and 35 in the body are perfectly circular and arepreferably cut by a gas torch or laser beam. Thus, those pieces of thehemispherical sections 14 and 16 which are removed to form the holes 26,28 and 35 are geometric shapes defined as "spherical segments".Preferably, all welds are carried out by electron beam welding so thatonly material from adjoining components is employed in the weld, ratherthan extraneous welding material, thereby providing a cleaner, strongerjoint and a weld which is more easily carried out.

As FIGS. 1, 2 and 3 show, the components forming body 12 of valve 10 aresymetrical and identical in shape and size, in so far as possible, so asto be interchangeable and thereby reduce manufacturing costs. Thecomponents are also symetrically arranged in accordance with basicgeometric shapes so as to avoid the problem associated with forming andassembling irregular shapes. Thus, as shown in FIG. 3, . the valve plate18 lies in a first plane P1, the circumferential edge 33 of hole 35 liesin a second plane P2 which is parallel to plane P1, the circumferentialedge 25 of the flow hole 26 lies in a third plane P3, and thecircumferential edge 27 of the flow hole 28 lies in a fourth plane P4which is parallel to plane P3. The axial centerlines CL1 and CL2 of theflow tubes 22 and 24 are axially alighed with a centerline CL3 whichextends between the centerpoints CP1 and CP2 of the holes 26 and 28. Theaxial centerline CL4 of sleeve 30 passes through centerpoint CP3 ofvalve plate 18 (and through the centerpoint of the aperture 20 therein).The centerpoint CP3 is located at the midpoint of centerline CL3. Thecenterline CL4 lies in a plane which is perpendicular to plane P1. Thisarrangement of the holes 26, 28 and 35 is the simplest from a geometricstandpoint and simplifies jigging the hemispheres and other componentsduring cutting, assembly and welding.

In the embodiment shown in FIG. 2, the valve seat 46 around aperture 20in valve plate 18 is conical and the valve disc 44 is provided with aconical mating surface 43 to provide a "plug type" valve seatingarrangement.

In the embodiment shown in FIG. 7, a "flat-lapped" valve seatarrangement is shown in which a raised or projecting annular valve seat46A is provided on valve plate 18 for engagement with a raised flatmating surface 43A on the valve disc 44. The plate 18 and valve disc 44are made of hardened metal in both FIGS. 2 and 7.

In the embodiment shown in FIG. 8, a "Babbit" or soft metal seatingarrangement is shown in which a hardened raised or projecting valve seat46A is provided on valve plate 18 for engagement with a flat matingsurface 43B of an annular soft metal insert 43C located in an annularrecess 43D in valve disc 44.

In the embodiment shown in FIG. 2, the sealing or packing material takesthe form of a compressible or deformable washer 78 fabricated of packingor stuffing material and disposed around the unthreaded portion 55 ofvalve spindle 36 and between a flat end surface 81 of sleeve 30 and aflat shoulder or end wall surface 83 in the bore 84 in bonnet 74. Thenarrower portion 86 of bore 84 through which the unthreaded portion 55of valve spindle 36 extends is provided with two annular grooves 88 inwhich the O-rings 80 are located. When the bonnet 74 is screwed downtight, the washer 78 deforms and tightly seals the space between theunthreaded portion 55 of spindle 36 and the wall of the bore 90 insleeve 30, as well as the space between portion 55 and the narrower boreportion 86 in the bonnet 74.

In the embodiment shown in FIGS. 9 through 12, the sealing or packingarrangements are understood to be substantially the same as shown inFIG. 2.

In the embodiment shown in FIG. 13, several packing rings 92, one abovethe other, are provided beneath the washer 78 and the O-rings areomitted.

FIGS. 2, 9, 10, 11 and 12 show bonnets 74 of various configurations asregards tool-engaging surfaces whereby the bonnets are screwed andunscrewed. FIGS. 2, 9 and 10 show a hex-head nut configuration havingsix flats 94. FIGS. 11 and 12 show a nut configuration having two flats96.

FIGS. 2, 9, 11 and 14 show different arrangement for securing valvesleeve 30 to the hemispheric section 16 in communication with thecircular hole 35 . In FIGS. 2 and 13 the end edge 98 of sleeve 30 iswelded as at 87 to the lower portion of a conically shaped or chamferededge 89 of hole 35. In FIG. 9 sleeve 30 includes a shoulder 85 at itslower end which engages the inner surface of hemispheric section 16adjacent and beneath the chamfered edge 89 of hole 35 where weldingoccurs as at 87. In FIG. 11 a reduced diameter cylindrical portion 98 atthe lower end of sleeve 30 fits within the flat edge 91 of hole 35 andis welded in place as at 93. In FIG. 14, sleeve 30 is provided withexternal threads 95 at its lower end and these engage internal threads97 formed in the bore of a hollow cylindrical weld ring 100 which iswelded as at 101 to the lower portion of chamfered edge 83 of hole 35.

We claim:
 1. A valve (60) comprising:a hollow valve body (12) having ahole (35) therein; a hollow sleeve (30) secured to said body (12) andhaving a sleeve bore therethrough communicating with said hole (35);said sleeve (30) having a flat annular outer end surface (81), anexternally threaded portion (34) and an internally threaded portion(32); a valve spindle (36) extending through said sleeve (30) and havingan unthreaded portion (55) and an externally threaded portion (38)threadably engaged with said internally threaded portion (32) of saidsleeve (30) whereby rotation of said spindle (36) effects axial movementof said spindle (36) relative to said sleeve (30); a bonnet (74) havinga bonnet bore (84) therethrough for accommodating said sleeve (30) andsaid spindle (36) and having an internally unthreaded portion (86) forreceiving said unthreaded portion (55) of said valve spindle (36) andhaving an internally threaded portion (76) in said bonnet bore (84)threadably engaged with said externally threaded portion (34) of saidsleeve (30), said bonnet (74) having a flat annular flange (83)extending inwardly into said bonnet bore (84), said unthreaded portion(86) of said bonnet bore (84) having a plurality of annular grooves (88)formed therein; first compressible deformable packing material sealingmeans (78) entrapped in said bonnet bore (84) between said flat annularflange (83) and said flat annular outer end surface (81) of said sleeve(30); and second resiliently compressible deformable resilient sealingmeans in the form of O-rings (80) entrapped in said grooves (88) betweensaid bonnet (84) and said unthreaded portion (55) of said valve spindle(36).
 2. A valve (10) according to claim 1 wherein said sleeve comprisesan internally threaded first portion (100) connected to said valve body(12) and an internally and externally threaded detachable second portion(30) threadedly engaged with said first portion (100), said internallyand externally threaded portions of said sleeve being located on saidsecond portion (30).
 3. A valve comprising:a hollow valve body having acircular hole therein; a hollow cylindrical sleeve having a smoothexterior portion extending into said hole and secured to said body bywelding and having a sleeve bore therethrough communicating with saidhole; said sleeve having a flat annular outer end, an externallythreaded portion and an internally threaded portion; a valve spindleextending through said sleeve and having an unthreaded cylindricalportion and an externally threaded portion threadably engaged with saidinternally threaded portion of said sleeve whereby rotation of saidspindle effects axial movement of said spindle relative to said sleeve;a bonnet having a bonnet bore therethrough for accommodating said sleeveand said spindle, said bonnet bore having a relatively wide threadedportion threadably engaged with said externally threaded portion of saidsleeve and having an internally unthreaded portion of smaller diameterthan said relatively wide internally threaded portion for accommodatingsaid unthreaded cylindrical portion of said valve spindle, saidunthreaded portion having a plurality of annular grooves formed therein,said bonnet having a flat inwardly extending annular flange in saidbonnet bore between said threaded and unthreaded portions of said bonnetbore; first compressible deformable packing material sealing meansentrapped in said relatively wide portion of said bonnet bore betweensaid flat annular flange and said flat annular outer end of said sleeve;and second resiliently compressible sealing means in the form of O-ringsentrapped in said annular grooves in said bonnet bore between saidsleeve and said valve spindle.
 4. A valve according to claim 3 whereinsaid sleeve comprises an internally threaded first portion connected tosaid valve body and an internally and externally threaded separablesecond portion threadedly engaged with said first portion, saidinternally and externally threaded portions of said sleeve being locatedon said separable second portion.